According to the state of the art, for the realization of high temperature superconductors of high current-carrying capacity, these ceramic materials must be present in certain preferred orientations of the microstructure. Until now, it has been possible to produce thin layers of such structure only through deposition from the gas phase. Zirconium dioxide (ZrO.sub.2), magnesium oxide (MgO), strontium titanate (SrTiO.sub.3) and other materials of adapted coefficients of expansion and lattice structure were primarily used as substrates. On appropriately oriented monocrystal surfaces of these substrate materials, epitaxial growth of the HTSC material is possible.
The production of such thin preferentially oriented layers of the various HTSC materials known until now, such as Y-Ba-Cu-O or Bi-Sr-Ca-Cu-O or Tl-Ba-Ca-Cu-O (without indication of the stoichiometry in each case), has occurred by conventional methods of PVD technology (physical vapor deposition), such as for example by cathode sputtering of sintered HTSC targets by means of DC voltage, high-frequency, and magnetron methods. The production of preferentially oriented layers of high current carrying capacity has also been possible by vaporization of the individual elements from separate crucibles in an oxygen atmosphere as well as by vaporization of HTSC targets with the aid of excimer laser pulses.
An essential precondition for the production of oriented materials at a reasonable cost is a sufficiently fast rate of growth. With the current PVD methods, this rate is so slow that only specific applications in microelectronics enter into consideration. Growth rates as demanded in the practice are reached only with laser vaporization.
It is therefore an object of the invention to provide a method for the production of HTSC layers with which similarly high growth rates as in laser vaporization are obtained. In addition, the cathodes used therein are to be obtained.